The goal of this research is to express the malaria CSP gene in human cells using adenovirus type 5 as the vector, and to evaluate the potential of this recombinant virus as a vaccine. The malaria CSP gene was inserted into the E3 region of the Ad5 genome, this recombinant DNA was used to transfect HeLa cells. Recombinant virus that carried the CSP gene was selected and screened for the expression of CSP in human cells. Five such viruses were found, and both ELISA and Indirect Immunofluorescence methods were used to confirm that CSP was produced in the virus infected cells. Syrian hamsters were used to evaluate the immune response to these recombinant Ad5 viruses. Two to three week old Golden Syrian hamsters were anesthetized with Vetalar, and 10 to the seventh power to 10 to the eighth power pfu of virus was administered intranasally on day 1 and day 30. No antibody was detected against CSP one month after either inoculation, although strong antibody titer against Ad5 virus was found in the blood. T cell proliferation assay on spleen lymphocytes, using three synthetic peptides containing known T cell epitopes, failed to identify any T helper cells. Recombinant CSP produced in yeast does stimulate T cell proliferation, but the effect of contaminating yeast proteins has not yet been fully determined. Experiments are underway to determine the specificity of these responding T cells.